Changeset 218

Timestamp:

09/30/06 14:22:21 (2 years ago)

Author:

jwalt

Message:

• fix usage of PRNG
  
• make logging end-user compatible
  

Files:

• trunk/plugins/authenticate (modified) (9 diffs)

trunk/plugins/authenticate

@@ -18 +18 @@
-use Digest::MD5 qw(md5_base64 md5_hex md5);
-use MIME::Base64;
+use Config;
-use bytes;
-use constant DEFAULT_REALM => 'Protected Area';
@@ -226 +227 @@
-}
-
-sub _secret() {
-    # MersenneTwister is not a cryptographically secure PRNG unless fed through a hash function.
-    return md5(&rand());
-}
-
-# a secret used to protect first-time requests
-
+ = ''
-
-sub init {
-    my $self = shift;
+
+    # Poor randomness, but all we might have.
+    *_secret = sub { md5(rand().time().$_SERVER_SECRET) };
-
-    # Try to get secure random numbers. Without, security does not withstand reasonably determined attack.
-    eval {
-        require Math::Random::MT::Auto;
-        Math::Random::MT::Auto->import('rand','srand');
-        my $init;
-&srand('/dev/
-&
+Math::Random::MT::Auto::srand('/dev/u
+Math::Random::MT::Auto::
-        $self->log(LOGWARN,"Could not seed PRNG. You need to call Math::Random::MT::Auto::srand yourself.") unless $init;
+
+        # MersenneTwister is not cryptographically secure by itself. The authors suggest using
+        # a hash over eight random values.
+        *secret = sub { md5( join("",map({ Math::Random::MT::Auto::irand() } 1..8)) . $_SERVER_SECRET ); };
-    };
-    $self->log(LOGWARN,"Could not load suitable PRNG. Digest auth will be insecure. Please install Math::Random::MT::Auto.") if ($@);
-
-
+&
-    cleanup();
-}
-
-secret and username
+and secret
-my %_SESSIONS;
-
@@ -300 +302 @@
-        $_SESSIONS{$session}[0] = 1;
-        $_SESSIONS{$session}[1] = int($timestamp);
-
+&
-    } else {
-        undef $session;
-    }
-
-
+&
-    $nonce .= md5($nonce . $secret);
-    my $header = "Digest realm=" . quoted_string($self->config->auth_realm) . ", " .
@@ -313 +315 @@
-        "stale=" . (defined $session?'true':'false') . ", " .
-        "nonce=".quoted_string(encode_base64($nonce,""));
-INFO
+DEBUG
-    $self->client->headers_out->header("WWW-Authenticate",$header);
-    $self->client->headers_out->header_remove('Authentication-Info');
@@ -335 +337 @@
-
-    my $auth = $hd->header('Authorization');
-INFO, "$want_type ".(defined $auth?"(got: $auth)":"(no authorization header)")
+DEBUG, ucfirst($want_type) . " authentication for realm " . $self->config->auth_realm
-
-    no warnings "uninitialized";
@@ -419 +421 @@
-        # If the nonce doesn't match what it should be, something fishy is going on: A user tries to act as a different user, 
-        # take over another user's session id, or it could be a replay attack.
-, however
+
-        my $secret = ( $s? $$s[2] : $_SERVER_SECRET );
-        $nonce = "$timestamp:$session:$user:" . md5("$timestamp:$session:$user:$secret");
@@ -445 +447 @@
-
-        # Create response authentication.
- # TODO: provide auth-int? . ($param{qop} eq 'auth-int'? ':' . $bodyhash : '')
+
-        $response = md5_hex( $hash->[0] . ':' . encode_base64($param{nonce},"") . ':' .
-                                $param{nc} . ':' . $param{cnonce} . ':' . 'auth' . ':' .
-                                $A2 );
-        $self->client->headers_out->header('Authentication-Info',"qop=auth, cnonce=".quoted_string($param{cnonce}).", nc=$param{nc}, rspauth=".quoted_string($response));
+        # TODO: providing qop=auth-int on resonses is difficult at best. Browsers don't seem to accept
+        # headers in chunked encoding trailer, and calculating the body hash up front can result in a
+        # tremendous performance impact. I assume the major browsers don't check it anyway, so let it be for now. 
-
-        $hd->header('Digest-Session',$session);
-        if (!defined $_SESSIONS{$session}[0]) {
-successful login, establish server-side state
+Successful login, establish server-side state.
-            $_SESSIONS{$session} = [ -1 ];
-            $self->send('login',$param{username});
-
-
+
-            return $self->send_digest_challenge($session,$param{username});
-        }
@@ -465 +469 @@
-            # Change nonce once per minute to reduce replay attack time window.
-            return $self->send_digest_challenge($session,$param{username}) if $timestamp < time()-60;
+            $self->log(LOGINFO, "Identified user as $param{username} via Digest");
-            return OK;
-        }
@@ -472 +477 @@
-
-        # All checks passed.
+        $self->log(LOGINFO, "Identified user as $param{username} via Digest");
-        return OK;
-    }